Ophthalmic compositions for treating ocular hypertension

ABSTRACT

This invention relates to potent potassium channel blocker compounds of Formula (I) or a formulation thereof for the treatment of glaucoma and other conditions which leads to elevated intraoccular pressure in the eye of a patient. This invention also relates to the use of such compounds to provide a neuroprotective effect to the eye of mammalian species, particularly humans, or a pharmaceutically acceptable salt, in vivo hydrolysable ester, enantiomer, diastereomer or mixture thereof: formula (II) represents C 6-10  aryl or C 3-10  heterocyclyl, said aryl or heterocyclyl optionally substituted with 1-3 groups selected from R a ; Z represents (CH 2 ) n PO(OR)(OR*).

This application claims the benefit under 35 U.S.C. 119(e) of U.S.Provisional Application No. 60/500,095 filed Sep. 4, 2003.

BACKGROUND OF THE INVENTION

Glaucoma is a degenerative disease of the eye wherein the intraocularpressure is too high to permit normal eye function. As a result, damagemay occur to the optic nerve head and result in irreversible loss ofvisual function. If untreated, glaucoma may eventually lead toblindness. Ocular hypertension, i.e., the condition of elevatedintraocular pressure without optic nerve head damage or characteristicglaucomatous visual field defects, is now believed by the majority ofophthalmologists to represent merely the earliest phase in the onset ofglaucoma.

There are several therapies for treating glaucoma and elevatedintraocular pressure, but the efficacy and the side effect profiles ofthese agents are not ideal. Recently potassium channel blockers werefound to reduce intraocular pressure in the eye and therefore provideyet one more approach to the treatment of ocular hypertension and thedegenerative ocular conditions related thereto. Blockage of potassiumchannels can diminish fluid secretion, and under some circumstances,increase smooth muscle contraction and would be expected to lower IOPand have neuroprotective effects in the eye. (see U.S. Pat. Nos.5,573,758 and 5,925,342; Moore, et al., Invest. Ophthalmol. Vis. Sci 38,1997; WO 89/10757, WO94/28900, and WO 96/33719).

SUMMARY OF THE INVENTION

This invention relates to the use of potent potassium channel blockersor a formulation thereof in the treatment of glaucoma and otherconditions which are related to elevated intraocular pressure in the eyeof a patient. This invention also relates to the use of such compoundsto provide a neuroprotective effect to the eye of mammalian species,particularly humans. More particularly this invention relates to thetreatment of glaucoma and/or ocular hypertension (elevated intraocularpressure) using novel phosphate containing indazole compounds having thestructural formula I:

or a pharmaceutically acceptable salt, in vivo hydrolysable ester,enantiomer, diastereomer or mixture thereof:wherein,R represents hydrogen, or C₁₋₆ alkyl;R^(c) and R^(d) independently represent hydrogen or halo;R^(e) represents N or O;X represents —(CHR₇)_(p)—, —(CHR₇)_(p)CO—;Y represents —CO(CH₂)_(n)—, CH₂, or —CH(OR)—;Q represents CRy;Ry represents H, or C₁₋₆ alkyl;R_(w) represents H, C₁₋₆ alkyl, —C(O)C₁₋₆ alkyl, —C(O)OC₁₋₆ alkyl,—SO₂N(R)₂, —SO₂C₁₋₆ alkyl, —SO₂C₆₋₁₀ aryl, NO₂, CN or —C(O)N(R)₂;R₂ represents hydrogen, C₁₋₁₀ alkyl, OH, C₂₋₆ alkenyl, C₁₋₆ alkylSR,—(CH₂)_(n)O(CH₂)_(m)OR, —(CH₂)_(n)C₁₋₆ alkoxy, —(CH₂)_(n)C₃₋₈cycloalkyl, —(CH₂)_(n)C₃₋₁₀ heterocyclyl, —N(R)₂, —COOR, or—(CH₂)_(n)C₆₋₁₀ aryl, said alkyl, heterocyclyl, or aryl optionallysubstituted with 1-3 groups selected from R^(a);R₃ represents hydrogen, C₁₋₁₀ alkyl, —(CH₂)_(n)C₃₋₈ cycloalkyl,—(CH₂)_(n)C₃₋₁₀ heterocyclyl, —(CH₂)_(n)COOR, —(CH₂)_(n)C₆₋₁₀ aryl,—(CH₂)_(n)NHR₈, —(CH₂)_(n)N(R)₂, —(CH₂)_(n)N(R₈)₂, —(CH₂)_(n)NHCOOR,—(CH₂)_(n)N(R₈)CO₂R, —(CH₂)_(n)N(R₈)COR, —(CH₂)_(n)NHCOR,—(CH₂)_(n)CONH(R₈), aryl, —(CH₂)_(n)C₁₋₆ alkoxy, CF₃, —(CH₂)_(n)SO₂R,—(CH₂)_(n)SO₂N(R)₂, —(CH₂)_(n)CON(R)₂, —(CH₂)_(n)CONHC(R)₃,—(CH₂)_(n)CONHC(R)₂CO₂R, —(CH₂)_(n)COR₈, nitro, cyano or halogen, saidalkyl, alkoxy, heterocyclyl, or aryl optionally substituted with 1-3groups of R^(a);or, R₂ and R₃ taken together with the intervening Q form a 3-10 memberedcarbocyclic or heterocyclic carbon ring optionally interrupted by 1-2atoms of O, S, C(O) or NR, and optionally having 1-4 double bonds, andoptionally substituted by 1-3 groups selected from R^(a);R₄ and R₅ independently represent hydrogen, C₁₋₆ alkoxy, OH, C₁₋₆ alkyl,COOR, SO₃H, —O(CH₂)_(n)N(R)₂, —O(CH₂)_(n)CO₂R, —OPO(OH)₂, CF₃, OCF₃,—N(R)₂, nitro, cyano, C₁₋₆ alkylamino, or halogen;

represents C₆₋₁₀ aryl or C₃₋₁₀ heterocyclyl, said aryl or heterocyclyloptionally substituted with 1-3 groups selected from R^(a);Z represents (CH₂)_(n)PO(OR)(OR*);R* represents hydrogen, or C₁₋₆ alkyl;R₇ represents hydrogen, C₁₋₆ alkyl, —(CH₂)_(n)COOR or —(CH₂)_(n)N(R)₂,R₈ represents —(CH₂)_(n)C₃₋₈ cycloalkyl, —(CH₂)_(n 3-10) heterocyclyl,C₁₋₆ alkoxy or —(CH₂)_(n)C₅₋₁₀ heteroaryl, —(CH₂)_(n)C₆₋₁₀ aryl saidheterocyclyl, aryl or heteroaryl optionally substituted with 1-3 groupsselected from R^(a);R^(a) represents F, Cl, Br, I, CF₃, N(R)₂, NO₂, CN, —COR₈, CONHR₈,—CON(R₈)₂, —O(CH₂)_(n)COOR, —NH(CH₂)_(n)OR, —COOR, —OCF₃, —NHCOR, —SO₂R,—SO₂NR₂, —SR, (C₁-C₆ alkyl)O—, —(CH₂)_(n)O(CH₂)_(m)OR, —(CH₂)_(n)C₁₋₆alkoxy, (aryl)O—, —(CH₂)_(n)OH, (C₁-C₆ alkyl)S(O)_(m)—, H₂N—C(NH)—,(C₁-C₆ alkyl)C(O)—, (C₁-C₆ alkyl)OC(O)NH—, —(C₁-C₆alkyl)NR_(w)(CH₂)_(n)C₃₋₁₀ heterocyclyl-R_(w), —(C₁-C₆alkyl)O(CH₂)_(n)C₃₋₁₀ heterocyclyl-R_(w), —C₁-C₆ alkyl)S(CH₂)_(n)C₃₋₁₀heterocyclyl-R_(w), —(C₁-C₆ alkyl)-C₃₋₁₀ heterocyclyl-R_(w),—(CH₂)_(n)-Z-C(=Z²)N(R)₂, —(C₂₋₆ alkenyl)NR_(w)(CH₂)_(n)C₃₋₁₀heterocyclyl-R_(w), —(C₂₋₆ alkenyl)O(CH₂)_(n)C₃₋₁₀ heterocyclyl-R_(w),—C₂₋₆ alkenyl)S(CH₂)_(n)C₃₋₁₀ heterocyclyl-R_(w), —(C₂₋₆ alkenyl)-C₃₋₁₀heterocyclyl-R_(w), —(C₂₋₆ alkenyl)-Z¹-C(=Z²)N(R)₂, —(CH₂)_(n)SO₂R,—(CH₂)_(n)SO₃H, —(CH₂)_(n)PO(OR)₂, C₃₋₁₀cycloalkyl, C₆₋₁₀ aryl, C₃₋₁₀heterocyclyl, C₂₋₆ alkenyl, and C₁-C₁₀ alkyl, said alkyl, alkenyl,alkoxy, heterocyclyl and aryl optionally substituted with 1-3 groupsselected from C₁-C₆ alkyl, CN, NO₂, OH, CON(R)₂ and COOR;Z¹ and Z² independently represents NR_(w), O, CH₂, or S;g is 0-1;m is 0-3;n is 0-3; andp is 0-3.

This and other aspects of the invention will be realized upon inspectionof the invention as a whole.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to novel potassium channel blockers ofFormula I. It also relates to a method for decreasing elevatedintraocular pressure or treating glaucoma by administration, preferablytopical or intra-camaral administration, of a composition containing apotassium channel blocker of Formula I described hereinabove and apharmaceutically acceptable carrier. This invention is also concernedwith the use of a compound of formula I for the manufacture of amedicament for the treatment of ocular hypertension or glaucoma.

In an embodiment of the instant compounds are those compounds where p is1-3.

One embodiment of this invention is realized when Y is —CO(CH₂)_(n) andall other variables are as originally described. A subembodiment of thisinvention is realized when n is 0.

Another embodiment of this invention is realized when Y is CH(OR) andall other variables are as originally described.

Another embodiment of this invention is realized when Z is PO(OR)(OR*)and R and R* are H. A sub-embodiment of this invention is realized whenR and R* are C₁₋₆ alkyl.

In another embodiment R_(w) is selected from H, C₁₋₆ alkyl, —C(O)C₁₋₆alkyl and —C(O)N(R)₂ and all other variables are as originallydescribed.

In another embodiment X is —CHR₇)_(p)—, p is 1-3 and all other variablesare as originally described.

In another embodiment X is —CHR₇)_(p)CO—, p is 1-3 and all othervariables are as originally described.

In another embodiment

is a 6 membered heteroaryl or phenyl optionally substituted with 1-3groups selected from R^(a). A sub-embodiment of this invention isrealized when

is a pyridyl.

Yet another embodiment of this invention is realized when R₇ is hydrogenor C₁₋₆ alkyl, and all other variables are as originally described.

Still another embodiment of this invention is realized when Z isPO₃(OR)(OR*), R₂ and and R₃ independently are hydrogen, C₁₋₁₀ alkyl orC₁₋₆ alkylOH, and Y is —CO(CH₂)_(n)

Another embodiment of the instant invention is realized when R^(a) isselected from P, Cl, Br, I, CF₃, N(R)₂, NO₂, CN, —CONHR₈, —CON(R₈)₂,—O(CH₂)_(n)COOR, —NH(CH₂)_(n)OR, —COOR, —OCF₃, —NHCOR, —SO₂R, —SO₂NR₂,—SR, (C₁-C₆ alkyl)O—, —(CH₂)_(n)O(CH₂)_(m)OR, —(CH₂)_(n)C₁₋₆ alkoxy,(aryl)O—, —(CH₂)_(n)OH, (C₁-C₆ alkyl)S(O)_(m)—, H₂N—C(NH)—, (C₁-C₆alkyl)C(O)—, —(CH₂)_(n)PO(OR)₂, C₂₋₆ alkenyl, and C₁-C₁₀ alkyl, saidalkyl and alkenyl, optionally substituted with 1-3 groups selected fromC₁-C₆ alkyl, and COOR;

Examples of compounds of formula I of this invention are:

-   di-tert-butyl    4-{[1-(3,3-dimethyl-2-oxobutyl)-6-methoxy-1-H-indazole-3-yl]carbonyl}benzylphosphate;-   4-{[1-(3,3-dimethyl-2-oxybutyl)-6-methoxy-1-H-indazol-3-yl]carbonyl}benzyl    di-hydrogen phosphate;-   2-[(5-{[1-(3,3-dimethyl-2-oxobutyl-6-methoxy-1-H-indazol-3-yl)carbonyl}pyridine-2-yl)oxy]ethyl    di-hydrogen phosphate;-   (5-{[1-3,3dimethyl-2-oxobutyl)-6-methoxy-1H-indazol-3-yl]carbonyl}pyridine-2-yl)methyl    dihydrogen phosphate;-   2(5-{[1-(3,3dimethyl-2-oxobutyl)-6-methoxy-1H-indazol-3yl]carbonyl}pyridine-2-yl)-2,2-diflouroethyl    di-hydrogen phosphate; and-   2-(5-{[7-bromo-1-(3,3-dimethyl-2-oxobutyl)-6-methoxy-1H-indazol-3-yl]carbonyl}puyridin-2-yl)-2,2-difluoroethyl    di-hydrogen phosphate,    or a pharmaceutically acceptable salt, in vivo hydrolysable ester,    enantiomer, diastereomer or mixture thereof. A subembodiment of this    invention is realized when the compounds are in the form of a    mono-sodium or disodium salt.

The invention is described herein in detail using the terms definedbelow unless otherwise specified.

The compounds of the present invention may have asymmetric centers,chiral axes and chiral planes, and occur as racemates, racemic mixtures,and as individual diastereomers, with all possible isomers, includingoptical isomers, being included in the present invention. (See E. L.Eliel and S. H. Wilen Stereochemistry of Carbon Compounds (John Wileyand Sons, New York 1994), in particular pages 1119-1190)

When any variable (e.g. aryl, heterocycle, R¹, R⁶ etc.) occurs more thanone time in any constituent, its definition on each occurrence isindependent at every other occurrence. Also, combinations ofsubstituents/or variables are permissible only if such combinationsresult in stable compounds.

The term “alkyl” refers to a monovalent alkane (hydrocarbon) derivedradical containing from 1 to 10 carbon atoms unless otherwise defined.It may be straight, branched or cyclic. Preferred alkyl groups includemethyl, ethyl, propyl, isopropyl, butyl, t-butyl, cyclopropylcyclopentyl and cyclohexyl. When the alkyl group is said to besubstituted with an alkyl group, this is used interchangeably with“branched alkyl group”.

Cycloalkyl is a specie of alkyl containing from 3 to 15 carbon atoms,unless otherwise defined, without alternating or resonating double bondsbetween carbon atoms. It may contain from 1 to 4 rings, which are fused.Examples of such cycloalkyl elements include, but are not limited to,cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl.

Alkenyl is C₂-C₆ alkenyl.

Alkoxy refers to an alkyl group of indicated number of carbon atomsattached through an oxygen bridge, with the alkyl group optionallysubstituted as described herein. Said groups are those groups of thedesignated length in either a straight or branched configuration and iftwo or more carbon atoms in length, they may include a double or atriple bond. Exemplary of such alkoxy groups are methoxy, ethoxy,propoxy, isopropoxy, butoxy, isobutoxy, tertiary butoxy, pentoxy,isopentoxy, hexoxy, isohexoxy allyloxy, propargyloxy, and the like.

Halogen (halo) refers to chlorine, fluorine, iodine or bromine.

Aryl refers to aromatic rings e.g., phenyl, substituted phenyl and thelike, as well as rings which are fused, e.g., naphthyl, phenanthrenyland the like. An aryl group thus contains at least one ring having atleast 6 atoms, with up to five such rings being present, containing upto 22 atoms therein, with alternating (resonating) double bonds betweenadjacent carbon atoms or suitable heteroatoms. Examples of aryl groupsare phenyl, naphthyl, tetrahydronaphthyl, indanyl, biphenyl,phenanthryl, anthryl or acenaphthyl and phenanthrenyl, preferablyphenyl, naphthyl or phenanthrenyl. Aryl groups may likewise besubstituted as defined. Preferred substituted aryls include phenyl andnaphthyl.

The term heterocyclyl or heterocyclic, as used herein, represents astable 3- to 7-membered monocyclic or stable 8- to 11-membered bicyclicheterocyclic ring which is either saturated or unsaturated, and whichconsists of carbon atoms and from one to four heteroatoms selected fromthe group consisting of N, O, and S, and including any bicyclic group inwhich any of the above-defined heterocyclic rings is fused to a benzenering. The heterocyclic ring may be attached at any heteroatom or carbonatom which results in the creation of a stable structure. A fusedheterocyclic ring system may include carbocyclic rings and need includeonly one heterocyclic ring. The term heterocycle or heterocyclicincludes heteroaryl moieties. Examples of such heterocyclic elementsinclude, but are not limited to, azepinyl, benzimidazolyl,benzisoxazolyl, benzofurazanyl, benzopyranyl, benzothiopyranyl,benzofuryl, benzothiazolyl, benzothienyl, benzoxazolyl, chromanyl,cinnolinyl, dihydrobenzofuryl, dihydrobenzothienyl,dihydrobenzothiopyranyl, dihydrobenzothiopyranyl sulfone,dihydropyrrolyl, 1,3-dioxolanyl, furyl, imidazolidinyl, imidazolinyl,imidazolyl, indolinyl, indolyl, isochromanyl, isoindolinyl,isoquinolinyl, isothiazolidinyl, isothiazolyl, isothiazolidinyl,morpholinyl, naphthyridinyl, oxadiazolyl, 2-oxoazepinyl, oxazolyl,2-oxopiperazinyl, 2-oxopiperdinyl, 2-oxopyrrolidinyl, piperidyl,piperazinyl, pyridyl, pyrazinyl, pyrazolidinyl, pyrazolyl, pyridazinyl,pyrimidinyl, pyrrolidinyl, pyrrolyl, quinazolinyl, quinolinyl,quinoxalinyl, tetrahydrofuryl, tetrahydroisoquinolinyl,tetrahydroquinolinyl, thiamorpholinyl, thiamorpholinyl sulfoxide,thiazolyl, thiazolinyl, thienofuryl, thienothienyl, and thienyl.Preferably, heterocycle is selected from 2-azepinonyl, benzimidazolyl,2-diazapinonyl, dihydroimidazolyl, dihydropyrrolyl, imidazolyl,2-imidazolidinonyl, indolyl, isoquinolinyl, morpholinyl, piperidyl,piperazinyl, pyridyl, pyrrolidinyl, 2-piperidinonyl, 2-pyrimidinonyl,2-pyrollidinonyl, quinolinyl, tetrahydrofuryl, tetrahydroisoquinolinyl,and thienyl.

The term “heteroatom” means O, S or N, selected on an independent basis.

The term “heteroaryl” refers to a monocyclic aromatic hydrocarbon grouphaving 5 or 6 ring atoms, or a bicyclic aromatic group having 8 to 10atoms, containing at least one heteroatom, O, S or N, in which a carbonor nitrogen atom is the point of attachment, and in which one or twoadditional carbon atoms is optionally replaced by a heteroatom selectedfrom O or S, and in which from 1 to 3 additional carbon atoms areoptionally replaced by nitrogen heteroatoms, said heteroaryl group beingoptionally substituted as described herein. Examples of suchheterocyclic elements include, but are not limited to, benzimidazolyl,benzisoxazolyl, benzofurazanyl, benzopyranyl, benzothiopyranyl,benzofuryl, benzothiazolyl, benzothienyl, benzoxazolyl, chromanyl,cinnolinyl, dihydrobenzofuryl, dihydrobenzothienyl,dihydrobenzothiopyranyl, dihydrobenzothiopyranyl sulfone, furyl,imidazolyl, indolinyl, indolyl, isochromanyl, isoindolinyl,isoquinolinyl, isothiazolyl, naphthyridinyl, oxadiazolyl, pyridyl,pyrazinyl, pyrazolyl, pyridazinyl, pyrimidinyl, pyrrolyl, quinazolinyl,quinolinyl, quinoxalinyl, tetrahydroisoquinolinyl, tetrahydroquinolinyl,thiazolyl, thienofuryl, thienothienyl, thienyl and triazolyl. Additionalnitrogen atoms may be present together with the first nitrogen andoxygen or sulfur, giving, e.g., thiadiazole.

This invention is also concerned with compositions and methods oftreating ocular hypertension or glaucoma by administering to a patientin need thereof one of the compounds of formula I alone or incombination with one or more of the following active ingredients, incombination with a β-adrenergic blocking agent such as timolol,betaxolol, levobetaxolol, carteolol, levobunolol, a parasympathomimeticagent such as epinephrine, iopidine, brimonidine, clonidine,para-aminoclonidine, carbonic anhydrase inhibitor such as dorzolamide,acetazolamide, metazolamide or brinzolamide, an EP4 agonist (such asthose disclosed in WO 02/24647, WO 02/42268, EP 1114816, WO 01/46140,PCT Appln. No. CA2004000471, and WO 01/72268), a prostaglandin such aslatanoprost, travaprost, unoprostone, rescula, S1033 (compounds setforth in U.S. Pat. Nos. 5,889,052; 5,296,504; 5,422,368; and 5,151,444);a hypotensive lipid such as lumigan and the compounds set forth in U.S.Pat. No. 5,352,708; a neuroprotectant disclosed in U.S. Pat. No.4,690,931, particularly eliprodil and R-eliprodil as set forth in WO94/13275, including memantine; an agonist of 5-HT2 receptors as setforth in PCT/US00/31247, particularly1-(2-aminopropyl)-3-methyl-1H-imdazol-6-ol fumarate and2-(3-chloro-6-methoxy-indazol-1-yl)-1-methyl-ethylamine or a mixturethereof. An example of a hypotensive lipid (the carboxylic acid group onthe α-chain link of the basic prostaglandin structure is replaced withelectrochemically neutral substituents) is that in which the carboxylicacid group is replaced with a C₁₋₆ alkoxy group such as OCH₃ (PGF_(2a)1-OCH₃), or a hydroxy group (PGF_(2a) 1-OH).

Preferred potassium channel blockers are calcium activated potassiumchannel blockers. More preferred potassium channel blockers are highconductance, calcium activated potassium (Maxi-K) channel blockers.Maxi-K channels are a family of ion channels that are prevalent inneuronal, smooth muscle and epithelial tissues and which are gated bymembrane potential and intracellular Ca²⁺.

The present invention is based upon the finding that maxi-K channels, ifblocked, inhibit aqueous humor production by inhibiting net solute andH₂O efflux and therefore lower IOP. This finding suggests that maxi-Kchannel blockers are useful for treating other ophthamologicaldysfunctions such as macular edema and macular degeneration. It is knownthat lowering IOP promotes blood flow to the retina and optic nerve.Accordingly, the compounds of this invention are useful for treatingmacular edema and/or macular degeneration. This invention also relatesto the use of a compound of formula I for the manufacture of amedicament for the treatment of these diseases.

It is believed that maxi-K channel blockers which lower IOP are usefulfor providing a neuroprotective effect. They are also believed to beeffective for increasing retinal and optic nerve head blood velocity andincreasing retinal and optic nerve oxygen by lowering IOP, which whencoupled together benefits optic nerve health. As a result, thisinvention further relates to a method for increasing retinal and opticnerve head blood velocity, increasing retinal and optic nerve oxygentension as well as providing a neuroprotective effect or a combinationthereof. This invention also relates to the use of a compound of formulaI for the manufacture of a medicament for the treatment of thesediseases.

A number of marketed drugs function as potassium channel antagonists.The most important of these include the compounds Glyburide, Glipizideand Tolbutamide. These potassium channel antagonists are useful asantidiabetic agents. The compounds of this invention may be combinedwith one or more of these compounds to treat diabetes. This invention isalso concerned with the use of a compound of formula I for themanufacture of a medicament for the treatment of diabetes.

Potassium channel antagonists are also utilized as Class 3antiarrhythmic agents and to treat acute infarctions in humans. A numberof naturally occuring toxins are known to block potassium channelsincluding Apamin, Iberiotoxin, Charybdotoxin, Noxiustoxin, Kaliotoxin,Dendrotoxin(s), mast cell degranuating (MCD) peptide, and β-Bungarotoxin(β-BTX). The compounds of this invention may be combined with one ormore of these compounds to treat arrhythmias. This invention is alsoconcerned with the use of a compound of formula I in combination withthese compounds for the manufacture of a medicament for the treatment ofarrhythmias.

Depression is related to a decrease in neurotransmitter release. Currenttreatments of depression include blockers of neurotransmitter uptake,and inhibitors of enzymes involved in neurotransmitter degradation whichact to prolong the lifetime of neurotransmitters.

Alzheimer's disease is also characterized by a diminishedneurotransmitter release. Three classes of drugs are being investigatedfor the treatment of Alzheimer's disease cholinergic potentiators suchas the anticholinesterase drugs (e.g., physostigmine (eserine), andTacrine (tetrahydroaminocridine)); nootropics that affect neuronmetabolism with little effect elsewhere (e.g., Piracetam, Oxiracetam;and those drugs that affect brain vasculature such as a mixture ofergoloid mesylates amd calcium channel blocking drugs includingNimodipine. Selegiline, a monoamine oxidase B inhibitor which increasesbrain dopamine and norepinephrine has reportedly caused mild improvementin some Alzheimer's patients. Aluminum chelating agents have been ofinterest to those who believe Alzheimer's disease is due to aluminumtoxicity. Drugs that affect behavior, including neuroleptics, andanxiolytics have been employed. Anxiolytics, which are mildtranquilizers, are less effective than neuroleptics The presentinvention is related to novel compounds which are useful as potassiumchannel antagonists. This invention also relates to the use of acompound of formula I for the manufacture of a medicament for thetreatment of depression, and Alzheimer's.

The compounds of this invention may be combined with anticholinesterasedrugs such as physostigmine (eserine) and Tacrine(tetrahydroaminocridine), nootropics such as Piracetam, Oxiracetam,ergoloid mesylates, selective calcium channel blockers such asNimodipine, or monoamine oxidase B inhibitors such as Selegiline, in thetreatment of Alzheimer's disease. The compounds of this invention mayalso be combined with Apamin, Iberiotoxin, Charybdotoxin, Noxiustoxin,Kaliotoxin, Dendrotoxin(s), mast cell degranuating (MCD) peptide,β-Bungarotoxin (β-BTX) or a combination thereof in treating arrythmias.The compounds of this invention may further be combined with Glyburide,Glipizide, Tolbutamide or a combination thereof to treat diabetes.

The herein examples illustrate but do not limit the claimed invention.Each of the claimed compounds are potassium channel antagonists and arethus useful in the described neurological disorders in which it isdesirable to maintain the cell in a depolarized state to achieve maximalneurotransmitter release. The compounds produced in the presentinvention are readily combined with suitable and known pharmaceuticallyacceptable excipients to produce compositions which may be administeredto mammals, including humans, to achieve effective potassium channelblockage.

For use in medicine, the salts of the compounds of formula I will bepharmaceutically acceptable salts. Other salts may, however, be usefulin the preparation of the compounds according to the invention or oftheir pharmaceutically acceptable salts. When the compound of thepresent invention is acidic, suitable “pharmaceutically acceptablesalts” refers to salts prepared form pharmaceutically acceptablenon-toxic bases including inorganic bases and organic bases. Saltsderived from inorganic bases include aluminum, ammonium, calcium,copper, ferric, ferrous, lithium, magnesium, manganic salts, manganous,potassium, sodium, zinc and the like. Particularly preferred are theammonium, calcium, magnesium, potassium and sodium salts. Salts derivedfrom pharmaceutically acceptable organic non-toxic bases include saltsof primary, secondary and tertiary amines, substituted amines includingnaturally occurring substituted amines, cyclic amines and basic ionexchange resins, such as arginine, betaine caffeine, choline,N,N-dibenzylethylenediamine, diethylamin, 2-diethylaminoethanol,2-dimethylaminoethanol, ethanolamine, ethylenediamine,N-ethylmorpholine, N-ethylpiperidine, glucamine, glucosamine, histidine,hydrabamine, isopropylamine, lysine, methylglucamine, morpholine,piperazine, piperidine, polyamine resins, procaine, purines,theobromine, triethylamine, trimethylamine tripropylamine, tromethamineand the like. Preferred pharmaceutically acceptable salts are sodium andpotassium salts. However, to facilitate isolation of the salt duringpreparation, salts which are less soluble in the chosen solvent may bepreferred whether pharmaceutically acceptable or not.

When the compound of the present invention is basic, salts may beprepared from pharmaceutically acceptable non-toxic acids, includinginorganic and organic acids. Such acids include acetic, benzenesulfonic,benzoic, camphorsulfonic, citric, ethanesulfonic, fumaric, gluconic,glutamic, hydrobromic, hydrochloric, isethionic, lactic, maleic, malic,mandelic, methanesulfonic, mucic, nitric, pamoic, pantothenic,phosphoric, succinic, sulfuric, tartaric, p-toluenesulfonic acid and thelike. Particularly preferred are citric, hydrobromic, hydrochloric,maleic, phosphoric, sulfuric and tartaric acids.

The preparation of the pharmaceutically acceptable salts described aboveand other typical pharmaceutically acceptable salts is more fullydescribed by Berg et al., “Pharmaceutical Salts,” J. Pharm. Sci.,1977:66:1-19.

In vivo hydrolysable esters are those pharmaceutically acceptable estersthat hydrolyze in the human body to produce the parent compound. Suchesters can be identified by administering, eg. Intravenously to a testanimal, the compound under test and subsequently examining the testanimal's body fluids.

As used herein, the term “composition” is intended to encompass aproduct comprising the specified ingredients in the specific amounts, aswell as any product which results, directly or indirectly, fromcombination of the specific ingredients in the specified amounts.

When a compound according to this invention is administered into a humansubject, the daily dosage will normally be determined by the prescribingphysician with the dosage generally varying according to the age,weight, sex and response of the individual patient, as well as theseverity of the patient's symptoms.

The maxi-K channel blockers used can be administered in atherapeutically effective amount intravaneously, subcutaneously,topically, transdermally, parenterally or any other method known tothose skilled in the art.

Ophthalmic pharmaceutical compositions are preferably adapted fortopical administration to the eye in the form of solutions, suspensions,ointments, creams or as a solid insert. Ophthalmic formulations of thiscompound may contain from 0.01 ppm to 1% and especially 0.1 ppm to 1% ofmedicament. Higher dosages as, for example, about 10% or lower dosagescan be employed provided the dose is effective in reducing intraocularpressure, treating glaucoma, increasing blood flow velocity or oxygentension. For a single dose, from between 0.1 ng to 5000 ug, preferably 1ng to 500 ug, and especially 10 ng to 100 ug of the compound can beapplied to the human eye.

The pharmaceutical preparation which contains the compound may beconveniently admixed with a non-toxic pharmaceutical organic carrier, orwith a non-toxic pharmaceutical inorganic carrier. Typical ofpharmaceutically acceptable carriers are, for example, water, mixturesof water and water-miscible solvents such as lower alkanols oraralkanols, vegetable oils, polyalkylene glycols, petroleum based jelly,ethyl cellulose, ethyl oleate, carboxymethyl-cellulose,polyvinylpyrrolidone, isopropyl myristate and other conventionallyemployed acceptable carriers. The pharmaceutical preparation may alsocontain non-toxic auxiliary substances such as emulsifying, preserving,wetting agents, bodying agents and the like, as for example,polyethylene glycols 200, 300, 400 and 600, carbowaxes 1,000, 1,500,4,000, 6,000 and 10,000, antibacterial components such as quaternaryammonium compounds, phenylmercuric salts known to have cold sterilizingproperties and which are non-injurious in use, thimerosal, methyl andpropyl paraben, benzyl alcohol, phenyl ethanol, buffering ingredientssuch as sodium borate, sodium acetates, gluconate buffers, and otherconventional ingredients such as sorbitan monolaurate, triethanolamine,oleate, polyoxyethylene sorbitan monopalmitylate, dioctyl sodiumsulfosuccinate, monothioglycerol, thiosorbitol, ethylenediaminetetracetic acid, and the like. Additionally, suitable ophthalmicvehicles can be used as carrier media for the present purpose includingconventional phosphate buffer vehicle systems, isotonic boric acidvehicles, isotonic sodium chloride vehicles, isotonic sodium boratevehicles and the like. The pharmaceutical preparation may also be in theform of a microparticle formulation. The pharmaceutical preparation mayalso be in the form of a solid insert. For example, one may use a solidwater soluble polymer as the carrier for the medicament. The polymerused to form the insert may be any water soluble non-toxic polymer, forexample, cellulose derivatives such as methylcellulose, sodiumcarboxymethyl cellulose, (hydroxyloweralkyl cellulose), hydroxyethylcellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose;acrylates such as polyacrylic acid salts, ethylacrylates,polyactylamides; natural products such as gelatin, alginates, pectins,tragacanth, karaya, chondrus, agar, acacia; the starch derivatives suchas starch acetate, hydroxymethyl starch ethers, hydroxypropyl starch, aswell as other synthetic derivatives such as polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl methyl ether, polyethylene oxide, neutralizedcarbopol and xanthan gum, gellan gum, and mixtures of said polymer.

Suitable subjects for the administration of the formulation of thepresent invention include primates, man and other animals, particularlyman and domesticated animals such as cats and dogs.

The pharmaceutical preparation may contain non-toxic auxiliarysubstances such as antibacterial components which are non-injurious inuse, for example, thimerosal, benzalkonium chloride, methyl and propylparaben, benzyldodecinium bromide, benzyl alcohol, or phenylethanol;buffering ingredients such as sodium chloride, sodium borate, sodiumacetate, sodium citrate, or gluconate buffers; and other conventionalingredients such as sorbitan monolaurate, triethanolamine,polyoxyethylene sorbitan monopalmitylate, ethylenediamine tetraaceticacid, and the like.

The ophthalmic solution or suspension may be administered as often asnecessary to maintain an acceptable IOP level in the eye. It iscontemplated that administration to the mamalian eye will be about onceor twice daily.

For topical ocular administration the novel formulations of thisinvention may take the form of solutions, gels, ointments, suspensionsor solid inserts, formulated so that a unit dosage comprises atherapeutically effective amount of the active component or somemultiple thereof in the case of a combination therapy.

The following examples given by way of illustration is demonstrative ofthe present invention.

Definitions of the terms used in the examples are as follows:

SM—Starting material,

DMSO—dimethyl sulfoxide,

TLC—thin layer chromatography,

SGC—silica gel chromatography,

PhMgBr—phenylmagnesiumbromide

h=hr=hour,

THF—tetrahydrofuran,

DMF—dimethylformamide,

min—minute,

LC/MS—liquid chromatography/mass spectrometry,

HPLC—high performance liquid chromatography,

PyBOP—Benzotriazol-1-yloxytris-(dimethyl amino)phosphoniumhexafluorophosphate,

equiv=eq=equivalent,

NBS—N-Bromosuccinamide and

AIBN—2,2′-azobisisobutyronitrile.

The compounds of this invention can be made, with modification whereappropriate, in accordance with Schemes 1 through 5.

In Schemes 1 and 2 nitroanisole is brominated using NBS, AIBN andbenzoyl peroxide. Treatment of the bromonitroanisole with potassiumcyanide yielded the cyanonitroanisole. Conversion of the nitro group toan amine is accomplished by hydrogenation. The amine is then treatedwith sodium nitrite and HCl to yield the indazole ring. In this reactionas soon as the diazonium is generated by nitrosation of the anilinemoiety it is trapped intramolecularily by the acidic benzyl cyanide.Tautomerization of the resultant derivative gives the indazole nucleus.Treatment of the nitrile with a Gringard followed by hydrolysis of theresultant imino-magnesium complex gives the desired alkyl/aryl ketone.

In a 500 mL flask was charged 336 mmoles (13.44 g; 60%) of NaH. Underargon 150 mL of DMSO was added, followed by dropwise addition of 32 mLof ethyl cyanoacetate (2.2 equiv.; 352 mmloes) at 5 o C. After all theaddition the reaction was warmed upto room temperature over 1 h. 30 g ofstarting nitro benzene derivative was added (160 mmoles) as a powder.The reaction mixture was heated in a closed system at 90oC for 8 hours.Acidification and standard work-up gave a crude oily residue which waspurified over a silica-gel column to give 39 g of desired crystallineproduct which was decarboxylated to give the benzyl nitrile as follows.Thirty eight grams of SM obtained above was dissolved in 400 mL of 1Nsodium carbonate. The homogenous solution was stirred at rt for twodays. TLC analysis indicated competion of reaction. The reaction mixturewas acidified and extratced with ethyl acetate (100 mL×4). The combinedorganic phases was dried over sodium sulphate and concentrated andresidue was subjected to SGC to give the desired product.

1H NMR CDCL3: 7.72 (1H, d, J=3 Hz); 7.61 (1H, d, J=8.5 Hz); 7,25 (1H,dd, J=3 and 8.5 Hz); 4.17 (2H, s); 3.94 (3H, s). LCMS [M+H]=193.

PREPARATIVE EXAMPLE 2

10 g of benzylnitrile derivative was dissolved in THF 20 mL followed bydilution with 50 mL of methanol. The reaction mixture was taken in apressure tube, Pd—C(10% wt/10 mole %) was added and the reaction mixture was hydrogenatedat 40 psi. After the requisite amount of hydrogen for the reduction ofthe NO₂ group was consumed the reaction was stopped. TLC analysisindicated a spot to spot conversion. The reaction mixture was filteredover a pad of celite and the filtrate was concentrated to a solid andused in the next step directly. Crude aniline derivative (52 mmoles wasdissloved/suspended in 2N HCl (150 mL), cooled to 5° C. followed by theaddition of 5.4 g of sodium nitrite in 10 mL of water. The reactionmixture was allowed to stir for 1 h with gradual warming to roomtemperature. TLC analysis indicated complete consumption of SM and theformation of a new spot. The reaction mixture was extratced with ethylacetate (100 mL×4); organic phase was collected, dried and concentrated.The residue was purified by SGC to give desired product. LCMS [M+H]=174

PREPARATIVE EXAMPLE 3

Nitrile (1.5 g) obtained from Preparative Example 2 was dissolved in 20mL of dry THF and under argon 3 equiv. of PhMgBr (1M in THF) was addedat 5° C. The reaction mixture was stirred at room temperature for 1 h.The reaction was carefully quenched by addition of water and 1N HCl (15mL). The quenched reaction mixture was stirred at room temperature for 1hour then extracted with ethyl acetate (20 mL X3); combined organicphases were dried over sodium sulfate and concentrated to a solidresidue which was azeotroped with toluene three times. LCMS [M+H]=253

PREPARATIVE EXAMPLE 4

Weighed out 4.15 g of indazole and azeoptroped water with 2 toluene (100ml) washings, pulling off toluene azeotrope by rotovap. Dried thoroughlyunder high vaccuum and performed argon purges. Dissolved in 40 ml dryTHF and 92 ml dry ether under argon. Cooled to 5° C. in ice water bath.Charged 3 eq of isopropylmagnesium chloride ((6 ml of a 2M solution inTHF) and stired for 0.5 hr at room temp. Carefully charged 1N HCl (240ml) and stired for 1 h. Monitored reaction by TLC. Extracted with EtOAc,rotovaped and produced desired product.

LCMS [M+H]=219

PREPARATIVE EXAMPLE 5

Step A:

To a solution of dibromide (23.2 g, by-product of Example 1, step-3) inacetic acid was added sodium acetate (22.5 g). The mixture was placed inoil bath and refluxed for a couple of hours until reaction completed.The mixture was cooled to room temperature and then poured intoice/water to give desired compound as an off-white solid. The solid wasisolated by filtration and dried over nitrogen atmosphere.

¹H NMR (CDCl₃): δ 10.23 (1H, s); 8.19 (1H, d); 7.02 (1H, dd); 6.96 (1H,d); 3.90 (3H, s).Step B:

To the intermediate from Step A was added triethyl orthoformate (40 ml)and heated to 130° C. for a couple of hours. The resulting mixture wasconcentrated to dry to give title compound as a brown solid.

¹H NMR (DMSO): δ 10.08 (1H, s); 7.98 (1H, d); 7.25 (1H, d); 7.02 (1H,dd); 6.81 (1H, s); 3.82 (3H, s); 3.52 (4H, q); 1.11 (6H, t).

EXAMPLE 1

-   di-tert-butyl    4-{[1-(3,3dimethyl-2-oxobutyl)-6-methoxy-1-H-indazole-3-yl]carbonyl}benzylphosphate    Step 1    100 g of fluoro-acetophenone in 400 mL of ethylene glycol was    stirred at room temperature with hydrazine (0.624 mol, 20 g) for 4 h    after which the reaction mixture was heated to 150 C for 48 h. TLC    analysis indicated complete reaction. Partitioned the reaction    mixture into dichloromethane and brine. Dried organic phase over    sodium sulphate and evaporated to a solid. Re-crystallized from    hexane/dicholomethane gave indazole.

1H NMR (CDCL3): 7.5 (1H, d, 7.5 Hz); 6.8 (2H, m); 3.8 (3H, s); 2.55 (3H,s)

LCMS [M+H]=163Step 2

-   6-methoxy-3-methyl-1-H tert-butyl-6-methoxy-3-methyl-indazole    1-indazole carboxylate    78 g of indazole was dissolved in 1 L of MeCN containing 1.1 equiv    of tri-ethyl amine, 0.2 equiv of DMAP was cooled to −5 C; followed    by slow addition of Boc2O (1.1 equiv) in 200 mL of MeCN. After 2 h    of stirring the reaction at rt the reaction mixture was evaporated    to an oil which was partitioned between EtOAc and brine, dried over    sodium sulphate and evaporated. The residue was applied to a short    SGC and eluted with 15% EtOAc in hexane. Evaporation gave product.

1H NMR (CDCL3): 7.6 (1H, bs); 7.42 (1H, d, J=7.5 Hz); 6.85 (1H, dd); 3.8(3H, s); 2.5 (3H, s); 1.7 (9H, s)

LCMS [M+H]=263Step 3

100 g of indazole was dissolved in 600 mL of CCl4, followed by additionof 1.1 equiv of NBS and 0.2 equiv of Bz2O. Reaction mix was vac-purgedwith argon and set to reflux for 5 h in presence of light from a sunlamp. Reaction mixture was filtered over a pad of SG and concentrated.Residual oil was purified over a short SGC. 85 g of pure bromide wasobtained. Mixed fractions yielded di-bromo derivative

mono-bromide: 1H NMR (CDCL3): 7.7 (1H, d, 7.5 Hz); 7.6 (1H, bs); 6.95(1H, dd); 4.7 (2H, s); 3.9 (3H, s); 1.7 (9H, s);

-   di-bromide: 1H NMR (CDCL3): 8.05 (1H, d, J=7.5 Hz); 7.6 (1H, bs);    7.0 (1H,dd); 6.85 (1H, s); 3.9 (3H, s); 1.7 (9H, s);    Step 4-   3-(bromomethyl)-6-methoxy-t-butyl-3-formyl-6-methoxy-1-H-indazole    1-H-indazole-1-carboxylate    5 g of bromide was dissolved in 10 mL of DMSO, cooled to 0 Cfollowed    by addition of 2.5 equiv of TMANO (trimethyl amine N-oxide).    Reaction was stirred for 0.5 h then a standard work-up and SG pad    filteration gave desired product quantitatively. LCMS [M+H]=277

1H NMR (CDCL3): 10.2 (1H, s); 8.1 (1H, d, J=7.5 Hz); 7.6 (1H, bs); 7.0(1H, dd); 3.9 (3H, s); 1.7 (9H, s);Step 5

Glasswares were flame dried under high vacuum To neat iodo-benzylalcohol derivative (3.6 g, 10 mmol) in the flask was slowly addedisopropylMgCl (5 mL, 2M solution). After stirring at rt for 2 hr,indazole derivative (1.1 g, 4 mmol) in 15 mL THF was added. The reactionmixture was stirred at rt for 2 hr. LC-MS showed the reaction wascomplete. Pour the reaction mixture into 30 mL saturated NH4Cl, followedby adding 40 mL ether. The organic layer was separated, the aqueouslayer was extracted by ether (40 mL). The combined organic layers werewashed with saturated K2CO3 (2×30 mL), water (40 mL) and brine (20 mL).The solvent was removed, the residue was used for next step reactionwithout further purification. LCMS [M+H]=499Steps 6 and 7

To a solution of indazole (crude from step 5) in 20 mL dichloromethanewas added 5 g celite and 4.3 g of PCC (MW 215.56, ˜2 eq). The reactionmixture was stirred at rt for 2 hr. LC-MS showed the reaction wascompleted LCMS [M+H]=497. The reaction mixture was filtered. The solventwas removed, the residue was dissolved in 10 mL MeOH, and added 20 mL 2NHCl. After stirring for 1 hr at rt LCMS and TLC analysis indicatedcomplete reaction. The reaction mixture was extracted with EtOAc (2×30mL). The solvent was removed, the residue was used for next stepreaction without further purification. LCMS [M+H]=283Step 8

To a solution of indazole (342 mg crude prod from step 7, ˜10 mmol)) in15 mL acetone was added 1.5 g of K2CO3 and 1.5 mL Bromopinacolone (Mw179.06, d1.326, 2.0 g, 11 mmol). The reaction mixture was stirred at80oC in a seal tube for 2 hr. After filtered off salts, the solvent wasremoved, the residue was purified by HPFC to give white solid product.

1H NMR (CDCL3)=8.3 (3H, m); 7.5 (1H, d, J=7.5 Hz); 7.05 (1H, dd); 7.6(1H, bs); 5.4 (2H, s); 4.8 (2H, bs); 3.9 (3H, s); 1.38 (9H, s)

LCMS [M+H]=381Steps 9, and 10

-   di-t-butyl-4-{[1-(3,3-dimethyl-2-oxobutyl)-6-methoxy-1-H-indazol-3-yl]carbonyl}benzyl    phosphate

To a solution of indazole-benzyl alcohol derivative (1.02 g, 2.68 mmol)in 20 mL CHCl3 was added 15 mL 0.45 M 1H-tetrazole in CH3CN, followed byaddition of di-tert-butyl N,N-diethylphosphoramidite (0.8 mL, d0.896, Mw249.34, 2.87 mmol, 1.1 eq). After stirred for 30 min., cooled thereaction mixture to −40oC, and a solution of MCPBA (85%, 2 g, Mw 172.57,9.8 mmol) in 5 mL DCM was added. The reaction mixture was warmed to rtand stirred for 10 min. 10 mL 10% NaHSO3 solution was added to quenchexcess MCPBA. Stirred at rt for 15 min. The reaction mixture was workedup with ether and water. The organic layer was separated and washed withwater. The solvent was removed, the product (residue) was used for nextstep reaction (Example 2) without further purification.

EXAMPLE 2

To the crude product obtained in Step 10 of Example 1 was added HCL inEtOAc (HCl passed through EtOAc at 0 C for 5 min) and stirred at roomtemperature for 4 hours. The solvent was removed. The residue waspurified by reverse phase HPLC to yield the desired compound as a whitesolid product.

1H NMR (CD3OD): 8.25 (2H, d, J=7.5 Hz); 8.18 (1H, d, J=7.5 Hz); 7.6 (2H,d, J=7.5 Hz); 7.0 (1H, dd); 6.9 (1H, bs); 5.65 (2H, s); 5.1 (2H, bs);3.9 (3H, s); 1.35 (9H, s);

LCMS [M+H]=460

EXAMPLE 3

-   1-(3-{[6-(2-hydroxyethoxy)pyridin-3-yl]carbonyl-6-methoxy-1-H-indazol-1-yl)-3,3    dimethylbutan-2-one    Step A:-   6-chloropyridin-3-yl)-6-methoxy-1-H-indazol-3-yl)-methanone

To a solution of 5-iodo-2-chloropyridine (2.56 g, 10.78 mmol) in THF (10mL) was added iPrMgBr dropwise at −78° C. The reaction stirred for 1 hbefore Intermediate 1 (1.71 g, 6.10 mmol) was added as a solution in THF(5 mL). After 2 h and the reaction was quenched with 1N NaOH andextracted with EtOAc. The combined organic layers were washed withbrine, dried over MgSO₄, and concentrated in vacuo. To a solution of thecrude product in toluene (50 mL) was added MnO₂ (2.173 g, 25.0 mmol) andthe reaction mixture was heated to 130° C. After 1 h the reaction wascomplete, filtered through a celite pad, and concentrated in vacuo. Thecrude product was dissolved in THF (10 mL) and 4 mL of 1N HCl was addeddropwise. The reaction stirred at RT until TLC analysis indicatedcompletion. The reaction mixture was cooled to 0° C. and the solidprecipitate was collected. ¹H NMR (CD₃OD) δ: 3.900 (3H, s), 7.013 (1H,d), 7.062 (1H, s), 7.627 (1H, d), 8.672 (1H, d), 9.306 (1H, s).Step B:

-   1-{3-[6chloropyridin-3-yl)carbonyl]-6-methoxy-1-H-indazol-1-yl)-3,3-dimethylbutan-2-one

To a solution of the intermediate from Step A (1.00 g, 3.48 mmol) andCs₂CO₃ (3.396 g, 10.45 mmol) in DMF (14 mL) was added 1-chloropinacolone(0.681 mL, 5.22 mmol). After 40 min the reaction was complete andquenched with H₂O. The reaction mixture was extracted with EtOAc and thecombined organic layers were washed with H₂O, brine, dried over MgSO₄,and concentrated in vacuo to yield the desired product. ¹H NMR (CD₃OD)δ: 1.344 (9H, s), 3.888 (3H, s), 6.947 (1H, s), 7.043 (1H, d), 7.625(1H, d), 8.221 (1H, d), 8.624 (1H, d), 9.257 (1H, d).Step C:

-   1-{3-[6-(2-hydroxyethoxy)pyridin-3-yl)carbonyl]-6-methoxy-1-H-indazol-1-yl)-3,3    dimethylbutan-2-one

40.6 mg (1.036 mmol) of NaH (60% dispersion in mineral oil) was washed3× with hexane and dried under nitrogen. Ethylene glycol (1 mL) wasadded to the dry NaH and the reaction stirred for 20 min at 60° C. Tothe reaction mixture was added the intermediate from Step B (100 mg,0.259 mmol) as a solution in THF (1.5 mL). The reaction continued tostir overnight at 60° C. Upon completion, the THF was removed in vacuo,diluted with EtOAc, washed with H₂O, brine, dried over MgSO₄, andconcentrated in vacuo. The crude residue was purified via silica gelchromatography.

1.376 (9H, s), 3.889 (3H, s), 4.021 (2H, m), 4.608 (2H, m), 5.429 (2H,s), 6.543 (1H, s), 6.223 (1H, d), 7.054 (1H, d), 8.336 (1H, d), 8.541(1H, d), 9.310 (1H, s).

EXAMPLE 4

-   2-[(5-{[1-3,3-dimethyl-2-oxobutyl-6-methoxy-1-H-indazol-3-yl)carbonyl}pyridine-2-yl)oxy]ethyl    di-hydrogen phosphate    To a solution of the intermediate from Example 3, Step C (160 mg,    0.388 mmol) in CHCl₃ (5 mL) was added tetrazole (1.29 mL, 0.582    mmol, 0.45 M/CH₃CN) and di-tert-butyl diethylphosphoramidite (0.129    mL, 0.465 mmol) at RT. After 0.5 h the reaction was complete and    peracetic acid (0.072 mL, 0.582 mmol) was added at 0° C. The    reaction mixture was quenched with saturated sodium bisulfite,    diluted with EtOAc, washed with saturated sodium bicarbonate, H₂O,    and saturated NaCl, dried over MgSO₄, and evaporated to dryness in    vacuo. The crude residue was chromatographed on SiO₂. A solution of    the phosphate ester in EtOAc was cooled to 0° C. and 99% HCl gas was    bubbled into the mixture until saturation occurred. The solid    precipitate was collected and recrystallized from EtOAc/ether to    yield the final product.

¹H NMR (CD₃OD) δ: 1.350 (9H, s), 3.887 (3H, s), 4.353 (2H, m), 4.652(2H, m), 5.696 (2H, s), 6.929 (1H, s), 7.024 (1H, d), 7.072 (1H, d),8.199 (1H, d), 8.638 (1H, d), 9.217 (1H, s).

EXAMPLE 5

-   1-(3-{[6-(hydroxymethyl)pyridin-3-yl)carbonyl}-6-methoxy-1H-indazol-1-yl)-3,3-dimethylbutan-2-one    Step A:-   (6-methoxy-1H-indazol-3-yl)6-methylpyridin-3-yl)methanone

To a solution of 5-bromo-2-methylpyridine (736 mg, 4.31 mmol) in THF (15mL) was added nBuLi dropwise (2.156 mL, 5.39 mmol, 2.5 M in hexanes) at˜78° C. The reaction stirred for 1 h before Intermediate 1 (1.00 g, 3.59mmol) was added as a solution in THF (5 mL). The starting material wasconsumed after 2 h and the reaction was quenched with 1N NaOH andextracted with EtOAc. The combined organic layers were washed withbrine, dried over MgSO₄, and concentrated in vacuo. A solution of thecrude product in toluene (20 mL) was added MnO₂ (0.414 g, 4.77 mmol) andthe reaction mixture was heated to 130° C. After 1 h the reaction wascomplete, filtered through a celite pad, and concentrated in vacuo. Thecrude product was dissolved in THF and 4 mL of 1N HCl was addeddropwise. After 1 h reaction mixture was cooled to 0° C. and the solidprecipitate was collected. ¹H NMR (DMSO) δ: 2.553 (3H, s), 3.832 (3H,s), 7.000 (PHI d), 7.089 (1H, s), 7.451 (1H, d), 8.100 (1H, d), 8.430(1H, d), 9.220 (1H, s).Step B:

-   1-{6-methoxy-3-[6-methylpyridin-3-yl)carbonyl]-1H-indazol-1-yl)-3,3    dimethylbutan-2-one

This compound was made as described in Step B of Example 3.

¹H NMR (CDCl₃) δ: 1.38 (9H, s), 2.65 (3H, s), 3.85 (3H, s), 5.22 (2H,s), 6.56 (1H, s), 7.05 (1H, d), 7.32 (1H, d), 8.34 (1H, d), 8.45 (1H,d), 9.50 (1H, s).Step C:

-   1-(3-{[6-(hydroxymethyl)pyridin-3-yl)carbonyl]-1H-indazol-1-yl)-3,3-dimethylbutan-2-one

To a stirring solution of the intermediate from Step B (74 mg, 0.202mmol) in CH₂Cl₂ was added MCPBA (67 mg, 0.303 mmol) at 0° C. TLCindicated the reaction was complete after 1.5 h and the reaction mixturewas concentrated in vacuo. The crude residue was dissolved in EtOAc andwashed with saturated sodium bisulfite, H₂O, brine, dried over MgSO₄,and concentrated in vacuo. Purified via silica gel chromatography. TheN-oxide was dissolved in CH₂Cl₂ and TFAA was added dropwise at 0° C.After 2 h the reaction was concentrated in vacuo and purified via silicagel chromatography.

¹H NMR (CDCl₃)δ:1.373 (9H, s), 3.898 (3H, s), 4.882 (2H, s), 5.428 (2H,s), 6.564 (1H, s), 7.066 (1H, d), 7.429 (1H, d), 8.352 (1H, d), 8.581(1H, d), 9.541 (1H, s).

EXAMPLE 6

-   (5-{[1-3,3-dimethyl-2-oxobutyl)-6-methoxy-1H-indazol-3-yl]carbonyl}pyridine-2-yl)methyl    dihydrogen phosphate

This compound was prepared as described in Example 4 and the product wasrecrystallized from EtOAc and hexane.

¹H NMR (CD₃OD) δ: 1.340 (9H, s), 3.884 (3H, s), 5.235 (2H, d), 5.687(2H, s), 6.937 (1H, s), 7.036 (1H, d), 7.840 (1H, d), 8.210 (1H, d),8.797 (1H, d), 9.430 (1H, s).

EXAMPLE 7

-   1-(3-{[6-(1,1-difluoro-2-hydroxyethyl)pyridin-3-yl]carbonyl}-6-methoxy-1-indazol-1-yl)-3,3-dimethylbutan-2-one    Step A:

To a solution of 2-pyridineacetic acid, 5-bromo-α,α-difluoro-, ethylester (13.4 g; prepared according to “Ero, H.; Haneko, Y.; Sakamoto, T.Chem Pharm. Bull. 2000,48, 982.”) in ethanol was added sodiumborohydride (2.3 g) portion-wise at 0° C. After stirring at 0° C. for 1hour, the mixture was poured into water and extracted with ethylacetate. The organic layer was washed with 1N NaOH_(aq), brine, dried(MgSO₄), and concentrated under reduced pressure to afford crudealcohol. The crude alcohol in methylene chloride was added imidazole(4.1 g) and TBS—Cl (8.3 g) at 0° C. The mixture was stirred for 1 hour.The reaction was poured into 0.1 N HCl_(aq) extracted with methylenechloride. The organic layer was washed with brine, dried (MgSO₄) andevaporated. The residue was purified by silica gel (100% methylenechloride) to give desired compound as a colorless oil.

¹H NMR (CDCl₃): δ 8.75 (1H, d); 7.95 (1H, dd); 7.57 (1H, d); 4.20 (2H,t); 0.82 (9H, s); 0.02 (6H, s).Step B:

The desired compound was prepared by a procedure similar to the onedescribed for Example 3, Step A.

¹H NMR (DMSO): δ 9.35 (1H, d); 8.65 (1H, dd); 8.14 (1H, d); 7.88 (1H,d); 7.10 (1H, d); 7.03 (1H, dd); 4.05 (2H, t); 3.85 (3H, s).

LC-MS (M+H)=334.2.Step C:

The desired compound was prepared by a procedure similar to the onedescribed for Example 3, Step B. This compound was purified by silicagel (hexanes/ethyl acetate=1/1) and crystalized from hexanes/ethylacetate.

¹H NMR (CHCl₃): δ 9.53 (1H, d); 8.71 (1H, dd); 8.35 (1H, d); 7.88 (1H,d); 7.08 (1H, dd); 6.57 (1H, d); 5.44 (2H, s); 4.32 (2H, t); 3.91 (3H,s); 1.38 (9H, s).

LC-MS (M+H)=432.3.

EXAMPLE 8

-   2-(5-{[1-(3,3-dimethyl-2-oxobutyl)-6-methoxy-1H-indazol-3yl]carbonyl}pyridine-2-yl)-2,2-diflouroethyl    di-hydrogen phosphate

This compound was prepared as described in Example 4. The final productwas purified via reverse phase liquid chromatography (20-90%acetonitrile in H₂O).

¹H NMR (CD₃OD) δ: 1.341 (9H, s), 3.888 (3H, s), 4.586 (2H, m), 5.704(2H, s), 6.938 (1H, s), 7.046 (1H, d), 7.897 (1H, d), 8.215 (1H, d),8.727 (1H, d), 9.457 (1H, s).

EXAMPLE 9

-   2-(5-{[7-bromo-1-(3,3    dimethyl-2-oxobutyl)-methoxy-1H-indazol-3-yl]carbonyl}puyridin-2-yl)-2,2-difluoroethyl    di-hydrogen phosphate    Step A:

To the intermediate from Example 7, Step C in chloroform was addedbromine at 0° C. slowly. The reaction was stirred at 0° C. for 5 min andpoured into sodium bisulfite solution. The mixture was extracted withmethylene chloride. The organic layer was dried over MgSO₄ andconcentrated. The residue was purified by crystallization (hexanes/ethylacetate).

¹H NMR (CHCl₃): δ 9.51 (1H, d); 8.69 (1H, dd); 8.45 (1H, d); 7.88 (1H,d); 7.14 (1H, d); 5.97 (2H, s); 4.31 (2H, t); 4.04 (3H, s); 1.38 (9H,s).

LC-MS (M+H)=512.1.Step B:

The desired compound was prepared by a procedure similar to the onedescribed for Example 4. This compound was crystalized from ethylacetate.

1H NMR (CD3OD): δ 9.44 (1H, d); 8.74 (1H, dd); 8.39 (1H, d); 7.92 (1H,d); 7.28 (1H, d); 6.57 (1H, d); 6.08 (2H, s); 4.61 (2H, m); 4.01 (3H,s); 1.33 (9H, s).

EXAMPLE 10

-   1-(3-{[6-(2    hydroxyethyl)pyridine-3-yl]carbonyl}-6-methoxy-1H-indazol-1-yl)-3,3dimethylbutan-2-one    Step A:

To a solution of 2,5-dibromopyridine (2.4 g) in toluene was addedtributylallyltin (3.4 ml) and dichlorobis(triphenylphosphine) palladium(0.7 g) under nitrogen atmosphere. The mixture was refluxed for a coupleof hours and concentrated under reduced pressure. The residue wasre-dissolved in “wet ether” and added DBU (3 ml) slowly to give a cloudysolution. The mixture was filtered over a pad of silica gel andconcentrated. The residue was dissolved in methylenechloride/methanol=1/1 solution and cooled to ˜78° C. To this solutionwas bubbled though ozone until the reaction mixture became a blue color.The reaction was warmed to 0° C. and added sodium borohydride (0.5 g)portion-wise. After stirring at 0° C. for 1 hour, the mixture was pouredinto water and extracted with ethyl acetate. The organic layer waswashed with 1N NaOH_(aq), brine, dried (MgSO₄), and concentrated underreduced pressure to afford crude alcohol. The alcohol was purified bysilica gel (methylene chloride/ethyl acetate=1/1) to give desiredalcohol. To a solution of alcohol in methylene chloride was addedimidazole (0.4 g) and TBS—Cl (0.8 g) at 0° C. The mixture was stir for 1hour. The reaction was poured into 0.1 N HCl_(aq) extracted withmethylene chloride. The organic layer was washed with brine, dried(MgSO₄) and evaporated. The residue was purified by silica gel (100%methylene chloride) to give desired compound.

¹H NMR (CDCl₃): δ 8.61 (1H, d); 7.73 (1H, dd); 7.14 (1H, d); 3.97 (2H,t); 2.96 (2H, t); 0.86 (9H, s); -0.02 (6H, s).Step B:

The desired compound was prepared by a procedure similar to the onedescribed for Example 5, Steps A and B. This compound was purified bysilica gel (hexanes/ethyl acetate=1/3).

¹H NMR (CHCl₃): δ 9.53 (1H, d); 8.54 (1H, dd); 8.35 (1H, d); 7.37 (1H,d); 7.07 (1H, dd); 6.56 (1H, d); 5.45 (2H, s); 4.11 (2H, t); 3.90 (3H,s); 3.18 (2H, t); 1.38 (9H, s).

LC-MS (M+H)=396.2.

Functional Assays

A. Maxi-K Channel

The activity of the compounds can also be quantified by the followingassay.

The identification of inhibitors of the Maxi-K channel is based on theability of expressed Maxi-K channels to set cellular resting potentialafter transfection of both alpha and beta1 subunits of the channel inHEK-293 cells and after being incubated with potassium channel blockersthat selectively eliminate the endogenous potassium conductances ofHEK-293 cells. In the absence of maxi-K channel inhibitors, thetransfected HEK-293 cells display a hyperpolarized membrane potential,negative inside, close to E_(K) (−80 mV) which is a consequence of theactivity of the maxi-K channel. Blockade of the Maxi-K channel byincubation with maxi-K channel blockers will cause cell depolarization.Changes in membrane potential can be determined with voltage-sensitivefluorescence resonance energy transfer (FI dye pairs that use twocomponents, a donor coumarin (CC₂DMPE) and an acceptor oxanol(DiSBAC₂(3)).

Oxanol is a lipophilic anion and distributes across the membraneaccording to membrane potential. Under normal conditions, when theinside of the cell is negative with respect to the outside, oxanol isaccumulated at the outer leaflet of the membrane and excitation ofcoumarin will cause FRET to occur. Conditions that lead to membranedepolarization will cause the oxanol to redistribute to the inside ofthe cell, and, as a consequence, to a decrease in FRET. Thus, the ratiochange (donor/acceptor) increases after membrane depolarization, whichdetermines if a test compound actively blocks the maxi-K channel.

The HEK-293 cells were obtained from the American Type CultureCollection, 12301 Parklawn Drive, Rockville, Md., 20852 under accessionnumber ATCC CRL-1573. Any restrictions relating to public access to themicroorganism shall be irrevocably removed upon patent issuance.

Transfection of the alpha and beta1 subunits of the maxi-K channel inHEK-293 cells was carried out as follows: HEK-293 cells were plated in100 mm tissue culture treated dishes at a density of 3×10⁶ cells perdish, and a total of five dishes were prepared. Cells were grown in amedium consisting of Dulbecco's Modified Eagle Medium (DMEM)supplemented with 10% Fetal Bovine serum, 1×L-Glutamine, and1×Penicillin/Streptomycin, at 37° C., 10% CO₂. For transfection withMaxi-K hα(pCIneo) and Maxi-K hβ1(pIRESpuro) DNAs, 150 μl FuGENE6™ wasadded dropwise into 10 ml of serum free/phenol-red free DMEM and allowedto incubate at room temperature for 5 minutes. Then, the FuGENE6™solution was added dropwise to a DNA solution containing 25 μg of eachplasmid DNA, and incubated at room temperature for 30 minutes. After theincubation period, 2 ml of the FuGENE6™/DNA solution was added dropwiseto each plate of cells and the cells were allowed to grow two days underthe same conditions as described above. At the end of the second day,cells were put under selection media which consisted of DMEMsupplemented with both 600 μg/ml G418 and 0.75 μg/ml puromycin. Cellswere grown until separate colonies were formed. Five colonies werecollected and transferred to a 6 well tissue culture treated dish. Atotal of 75 colonies were collected. Cells were allowed to grow until aconfluent monolayer was obtained. Cells were then tested for thepresence of maxi-K channel alpha and beta1 subunits using an assay thatmonitors binding of ¹²⁵I-iberiotoxin-D19Y/Y36F to the channel. Cellsexpressing ¹²⁵-iberiotoxin-D19Y/Y36F binding activity were thenevaluated in a functional assay that monitors the capability of maxi-Kchannels to control the membrane potential of transfected HEK-293 cellsusing fluorescence resonance energy transfer (FRET) ABS technology witha VIPR instrument. The colony giving the largest signal to noise ratiowas subjected to limiting dilution. For this, cells were resuspended atapproximately 5 cells/ml, and 200 μl were plated in individual wells ina 96 well tissue culture treated plate, to add ca. one cell per well. Atotal of two 96 well plates were made. When a confluent monolayer wasformed, the cells were transferred to 6 well tissue culture treatedplates. A total of 62 wells were transferred. When a confluent monolayerwas obtained, cells were tested using the FRET-functional assay.Transfected cells giving the best signal to noise ratio were identifiedand used in subsequent functional assays.

For functional assays:

The transfected cells (2E+06 Cells/mL) are then plated on 96-wellpoly-D-lysine plates at a density of about 100,000 cells/well andincubated for about 16 to about 24 hours. The medium is aspirated of thecells and the cells washed one time with 100 μl of Dulbecco's phosphatebuffered saline (D-PBS). One hundred microliters of about 9 μM coumarin(CC₂DMPE)-0.02% pluronic-127 in D-PBS per well is added and the wellsare incubated in the dark for about 30 minutes. The cells are washed twotimes with 100 μL of Dulbecco's phosphate-buffered saline and 100 μl ofabout 4.5 μM of oxanol (DiSBAC₂(3)) in (mM) 140 NaCl, 0.1 KCl, 2 CaCl₂,1 MgCl₂, 20 Hepes-NaOH, pH 7.4, 10 glucose is added. Three micromolar ofan inhibitor of endogenous potassium conductance of HEK-293 cells isadded. A maxi-K channel blocker is added (about 0.01 micromolar to about10 micromolar) and the cells are incubated at room temperature in thedark for about 30 minutes.

The plates are loaded into a voltage/ion probe reader (VIPR) instrument,and the fluorescence emission of both CC₂DMPE and DiSBAC₂(3) arerecorded for 10 sec. At this point, 100 μL of high-potassium solution(mM): 140 KCl, 2 CaCl₂, 1 MgCl₂, 20 Hepes-KOH, pH 7.4, 10 glucose areadded and the fluorescence emission of both dyes recorded for anadditional 10 sec. The ratio CC₂DMPE/DiSBAC₂(3), before addition ofhigh-potassium solution equals 1. In the absence of maxi-K channelinhibitor, the ratio after addition of high-potassium solution variesbetween 1.65-2.0. When the Maxi-K channel has been completely inhibitedby either a known standard or test compound, this ratio remains at 1. Itis possible, therefore, to titrate the activity of a Maxi-K channelinhibitor by monitoring the concentration-dependent change in thefluorescence ratio.

The compounds of this invention were found to causeconcentration-dependent inhibition of the fluorescence ratio with IC₅₀'sin the range of about 1 nM to about 20 μM, more preferably from about 10nM to about 500 nM.

B. Electrophysiological Assays of Compound Effects on High-ConductanceCalcium-Activated Potassium Channels

Methods:

Patch clamp recordings of currents flowing through large-conductancecalcium-activated potassium (maxi-K) channels were made from membranepatches excised from CHO cells constitutively expressing the α-subunitof the maxi-K channel or HEK293 cells constitutively expressing both α-and β-subunits using conventional techniques (Hamill et al., 1981,Pflügers Archiv. 391, 85-100) at room temperature. Glass capillarytubing (Garner #7052 or Drummond custom borosilicate glass 1-014-1320)was pulled in two stages to yield micropipettes with tip diameters ofapproximately 1-2 microns. Pipettes were typically filled with solutionscontaining (MM): 150 KCl, 10 Hepes (4-(2-hydroxyethyl)-1-piperazinemethanesulfonic acid), 1 Mg, 0.01 Ca, and adjusted to pH 7.20 with KOH.After forming a high resistance (>10⁹ ohms) seal between the plasmamembrane and the pipette, the pipette was withdrawn from the cell,forming an excised inside-out membrane patch. The patch was excised intoa bath solution containing (mM): 150 KCl, 10 Hepes, 5 EGTA (ethyleneglycol bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid), sufficientCa to yield a free Ca concentration of 1-5 μM, and the pH was adjustedto 7.2 with KOH. For example, 4.193 mM Ca was added to give a freeconcentration of 1 μM at 22° C. An EPC9 amplifier (HEKA Elektronic,Lambrect, Germany) was used to control the voltage and to measure thecurrents flowing across the membrane patch. The input to the headstagewas connected to the pipette solution with a Ag/AgCl wire, and theamplifier ground was connected to the bath solution with a Ag/AgCl wirecovered with a tube filled with agar dissolved in 0.2 M KCl. Theidentity of maxi-K currents was confirmed by the sensitivity of channelopen probability to membrane potential and intracellular calciumconcentration.

Data acquisition was controlled by PULSE software (HEKA Elektronic) andstored on the hard drive of a MacIntosh computer (Apple Computers) forlater analysis using PULSEFIT (HEKA Elektronic) and Igor (Wavemetrics,Oswego, Oreg.) software.

Results:

The effects of the compounds of the present invention on maxi-K channelswas examined in excised inside-out membrane patches with constantsuperfusion of bath solution. The membrane potential was held at −80 mVand brief (100-200 ms) voltage steps to positive membrane potentials(typically +50 mV) were applied once per 15 seconds to transiently openmaxi-K channels. As a positive control in each experiment, maxi-Kcurrents were eliminated at pulse potentials after the patch wastransiently exposed to a low concentration of calcium (<10 nM) made byadding 1 mM EGTA to the standard bath solution with no added calcium.The fraction of channels blocked in each experiment was calculated fromthe reduction in peak current caused by application of the specifiedcompound to the internal side of the membrane patch. Compound wasapplied until a steady state level of block was achieved. K_(I) valuesfor channel block were calculated by fitting the fractional blockobtained at each compound concentration with a Hill equation. The K_(I)values for channel block by the compounds described in the presentinvention range from 0.01 nM to greater than 10 μM.

1. A compound of the structural formula I:

or a pharmaceutically acceptable salt, in vivo hydrolysable ester,enantiomer, diastereomer or mixture thereof: wherein, R representshydrogen, or C₁₋₆ alkyl; R^(c) and R^(d) independently representhydrogen or halo; R^(e) represents N or O; X represents —(CHR₇)_(p)—,—(CHR₇)_(p)CO—; Y represents —CO(CH₂)_(n)—, CH₂, or —CH(OR)—; Qrepresents CRy; Ry represents H, or C₁₋₆ alkyl; R_(w) represents H, C₁₋₆alkyl, —C(O)C₁₋₁₆ alkyl, —C(O)OC₁₋₆ alkyl, —SO₂N(R)₂, —SO₂C₁₋₆ alkyl,—SO₂C₆₋₁₀ aryl, NO₂, CN or —C(O)N(R)₂; R₂ represents hydrogen, C₁₋₁₀alkyl, OH, C₂₋₆ alkenyl, C₁₋₆ alkylSR, —(CH2)_(n)O(CH2)_(m)OR,—(CH₂)_(n)C₁₋₆ alkoxy, —(CH2)_(n)C₃₋₈ cycloalkyl, —(CH₂)_(n)C₃₋₁₀heterocyclyl, —N(R)₂, —COOR, or —(CH₂)_(n)C₆₋₁₀ aryl, said alkyl,heterocyclyl, or aryl optionally substituted with 1-3 groups selectedfrom R^(a); R₃ represents hydrogen, C₁₋₁₀ alkyl, —(CH₂)_(n)C₃₋₈cycloalkyl, —(CH₂)_(n)C₃₋₁₀ heterocyclyl, —(CH₂)_(n)COOR,—(CH₂)_(n)C₆₋₁₀ aryl, —(CH₂)_(n)NHR₈, —(CH₂)_(n)N(R)₂, —(CH₂)_(n)N(R₈)₂,—(CH₂)_(n)NHCOOR, —(CH₂)_(n)N(R₈)CO₂R, —(CH₂)_(n)N(R₈)COR,—(CH2)_(n)NHCOR, —(CH₂)_(n)CONH(R₈), aryl, —(CH₂)_(n)C₁₋₆ alkoxy, CF₃,(CH₂)_(n)SO₂R, —(CH₂)_(n)SO₂N(R)₂, —(CH2)_(n)CON(R)₂,—(CH₂)_(n)CONHC(R)₃, —(CH₂)_(n)CONHC(R)₂CO₂R, —(CH₂)_(n)COR₈, nitro,cyano or halogen, said alkyl, alkoxy, heterocyclyl, or aryl optionallysubstituted with 1-3 groups of R^(a); or, R₂ and R₃ taken together withthe intervening Q form a 3-10 membered carbocyclic or heterocycliccarbon ring optionally interrupted by 1-2 atoms of O, S, C(O) or NR, andoptionally having 1-4 double bonds, and optionally substituted by 1-3groups selected from R^(a); R₄ and R₅ independently represent hydrogen,C₁₋₆ alkoxy, OH, C₁₋₆ alkyl, COOR, SO₃H, —O(CH₂)_(n)N(R)₂,—O(CH₂)_(n)CO₂R, —OPO(OH)₂, CF₃, OCF₃, —N(R)₂, nitro, cyano, C₁₋₆alkylamino, or halogen;

represents C₆₋₁₀ aryl or C₃₋₁₀ heterocyclyl, said aryl or heterocyclyloptionally substituted with 1-3 groups selected from R^(a); Z represents(CH₂)_(n)PO(OR)(OR*); R* represents hydrogen, or C₁₋₆ alkyl; R₇represents hydrogen, C₁₋₆ alkyl, —CH2)_(n)COOR or —(CH₂)_(n)N(R)₂, R₈represents —(CH₂)_(n)C₃₋₈ cycloalkyl, —(CH₂)_(n 3-10) heterocyclyl, C₁₋₆alkoxy or —(CH₂)_(n)C₅₋₁₀ heteroaryl, —(CH₂)_(n)C₆₋₁₀ aryl saidheterocyclyl, aryl or heteroaryl optionally substituted with 1-3 groupsselected from R^(a); R^(a) represents F, Cl, Br, I, CF₃, N(R)₂, NO₂, CN,—COR₈, —CONHR₈, —CON(R₈)₂, —O(CH2)_(n)COOR, —NH(CH₂)_(n)OR, —COOR,—OCF₃, —NHCOR, —SO₂R, —SO₂NR₂, —SR, (C₁-C₆ alkyl)O—,—(CH₂)_(n)O(CH₂)_(m)OR, —(CH₂)_(n)C₁₋₆ alkoxy, (aryl)O—, —(CH₂)_(n)OH,(C₁-C₆ alkyl)S(O)_(m)—, H₂N—C(NH)—, (C₁-C₆ alkyl)C(O)—, (C₁-C₆alkyl)OC(O)NH—, —(C₁-C₆ alkyl)NR_(w)(CH₂)_(n)C₃₋₁₀ heterocyclyl-R_(w),—(C₁-C₆ alkyl)O(CH₂)_(n)C₃₋₁₀ heterocyclyl-R_(w), —C₁-C₆alkyl)S(CH₂)_(n)C₃₋₁₀ heterocyclyl-R_(w), —(C₁-C₆ alkyl)-C₃₋₁₀heterocyclyl-R_(w), —(CH₂)_(n)-Z¹-C(=Z²)N(R)₂, —(C₂₋₆alkenyl)NR_(w)(CH₂)_(n)C₃₋₁₀ heterocyclyl-R_(w), —C₂₋₆alkenyl)O(CH₂)_(n)C₃₋₁₀ heterocyclyl-R_(w), —(C₂₋₆alkenyl)S(CH₂)_(n)C₃₋₁₀ heterocyclyl-R_(w), —C₂₋₆ alkenyl)-C₃₋₁₀heterocyclyl-R_(w), —(C₂₋₆ alkenyl)-Z¹-C(=Z²)N(R)₂, —(CH₂)_(n)SO₂R,—(CH₂)_(n)SO₃H, —(CH₂)_(n)PO(OR)₂, C₃₋₁₀cycloalkyl, C₆₋₁₀ aryl, C₃₋₁₀heterocyclyl, C₂₋₆ alkenyl, and C₁-C₁₀ alkyl, said alkyl, alkenyl,alkoxy, heterocyclyl and aryl optionally substituted with 1-3 groupsselected from C₁-C₆ alkyl, CN, NO₂, OH, CON(R)₂ and COOR; Z¹ and Z²independently represents NR_(w), O, CH₂, or S; g is 0-1; m is 0-3; n is0-3; and p is 0-3.
 2. The compound according to claim 1 wherein Y is—CO(CH₂)_(n), p is 1-3 and X is —CHR₇)_(p) or —(CHR₇)_(p)CO—.
 3. Thecompound according to claim 2 wherein Z is PO(OR)(OR*), R₂ and R₃ areindependently hydrogen, C₁₋₁₀ alkyl or C alkylOH, Y is —CO(CH₂)_(n). 4.The compound according to claim 3 wherein

is a 6 membered heteroaryl or phenyl optionally substituted with 1-3groups selected from R^(a).
 5. A compound according to claim 4 wherein

is pyridyl optionally substituted with 1-3 groups selected from R^(a).6. A compound which is: di-tert-butyl4-{[1-(3,3-dimethyl-2-oxobutyl)-6-methoxy-1-H-indazole-3-yl]carbonyl}benzylphosphate;4-{[1-(3,3-dimethyl-2-oxybutyl)-6-methoxy-1-H-indazol-3-yl]carbonyl}benzyldi-hydrogen phosphate;2-[(5-{[1-(3,3-dimethyl-2-oxobutyl-6-methoxy-1-H-indazol-3-yl)carbonyl}pyridine-2-yl)oxy]ethyldi-hydrogen phosphate;(5-{[1-3,3dimethyl-2-oxobutyl)-6-methoxy-1H-indazol-3-yl]carbonyl}pyridine-2-yl)methyldihydrogen phosphate;2-(5-{[1-(3,3-dimethyl-2-oxobutyl)-6-methoxy-1H-indazol-3yl]carbonyl}pyridine-2-yl)-2,2-diflouroethyldi-hydrogen phosphate; and2-(5-{[7-bromo-1-(3,3-dimethyl-2-oxobutyl)-6-methoxy-1H-indazol-3-yl]carbonyl}puyridin-2-yl)-2,2-difluoroethyldi-hydrogen phosphate, or a pharmaceutically acceptable salt, in vivohydrolysable ester, enantiomer, diastereomer or mixture thereof.
 7. Acompound which is: di-tert-butyl4-{[1-(3,3-dimethyl-2-oxobutyl)-6-methoxy-1-H-indazole-3-yl]carbonyl}benzylphosphatein the form of a monosodium or disodium salt;4-{[3,3-dimethyl-2-oxybutyl)-6-methoxy-1-H-indazol-3-yl]carbonyl}benzyldi-hydrogen phosphate in the form of a monosodium or disodium salt;2-[(5-{[1-(3,3-dimethyl-2-oxobutyl-6-methoxy-1-H-indazol-3-yl)carbonyl}pyridine-2-yl)oxy]ethyldi-hydrogen phosphate in the form of a monosodium or disodium salt;(5-{[1-3,3-dimethyl-2-oxobutyl)-6-methoxy-1H-indazol-3-yl]carbonyl}pyridine-2-yl)methyldihydrogen phosphate in the form of a monosodium or disodium salt;2-(5-{[1-(3,3-dimethyl-2-oxobutyl)-6-methoxy-1H-indazol-3yl]carbonyl}pyridine-2-yl)-2,2-diflouroethyldi-hydrogen phosphate in the form of a monosodium or disodium salt; and2-(5-{[7-bromo-(3,3-dimethyl-2-oxobutyl)-6-methoxy-1H-indazol-3-yl]carbonyl}puyridin-2-yl)-2,2-difluoroethyldi-hydrogen phosphate in the form of a monosodium or disodium salt. 8.Use of a compound of formula I in claim 1 for the manufacture of amedicament for the treatment of ocular hypertension or glaucoma.
 9. Useof a compound of formula I in claim 1 for the manufacture of amedicament for the treatment of macular edema, macular degeneration,increasing retinal and optic nerve head blood velocity, increasingretinal and optic nerve oxygen tension, and/or a neuroprotective effect.10. Use of a compound of formula I in claim 1 for the manufacture of amedicament for preventing repolarization or hyperpolarization of amammalian cell containing potassium channel or for treating Alzheimer'sDisease, depression, cognitive disorders, and/or arrhythmia disorders.11. Use of a compound of formula I in claim 1 for the manufacture of amedicament for treating diabetes.
 12. A composition comprising acompound of formula I of claim 1 and a pharmaceutically acceptablecarrier.
 13. The composition according to claim 12 wherein the compoundof formula I is applied as a topical formulation, said topicalformulation administered as a solution or suspension and optionallycontaining xanthan gum or gellan gum.
 14. A composition according toclaim 13 wherein one or more of an active ingredient belonging to thegroup consisting of: β-adrenergic blocking agent, parasympatho-mimeticagent, sympathomimetic agent, carbonic anhydrase inhibitor, EP4 agonist,a prostaglandin or derivative thereof, hypotensive lipid,neuroprotectant, and/or 5-HT2 receptor agonist is optionally added. 15.A composition according to claim 14 wherein the β-adrenergic blockingagent is timolol, betaxolol, levobetaxolol, carteolol, or levobunolol;the parasympathomimetic agent is pilocarpine; the sympathomimetic agentis epinephrine, brimonidine, iopidine, clonidine, orpara-aminoclonidine, the carbonic anhydrase inhibitor is dorzolamide,acetazolamide, metazolamide or brinzolamide; the prostaglandin islatanoprost, travaprost, unoprostone, rescula, or S1033, the hypotensivelipid is lumigan, the neuroprotectant is eliprodil, R-eliprodil ormemantine; and the 5-HT2 receptor agonist is1-(2-aminopropyl)-3-methyl-1H-imdazol-1 fumarate or2-(3-chloro-6-methoxy-indazol-1-yl)-1-methyl-ethylamine.